Push-back cart storage systems use rolling carts for carrying pallets. By providing several carts on a set of rails, usable space between aisles in a warehouse is increased, since multiple pallets can be stored and retrieved from a single aisle. Consequently, aisle space necessary in conventional storage racks for forklift access may instead be used for additional storage racks, providing more efficient use of space.
In a push-back storage system, the each cart must sequentially fit under the next cart, from the front to the back of the rack. Consequently, in systems having multiple carts in a single lane, such as with three, four, five or six deep cart systems, the height of the highest cart necessary to accommodate the underlying carts may be substantial. Specifically, the highest cart must be high enough to accommodate all other carts underneath it. The height of the highest cart determines the vertical clearance required for each lane. As several lanes of storage are stacked vertically, the cart height contributes to the total vertical height of the rack system. Since the available vertical clearance in the warehouse may be limited, cart height can become a significant factor. The carts may carry in excess of 3000 lbs of goods on a pallet. Consequently, the carts must have sufficient structural strength to resist heavy loading. On the other hand, it is advantageous to simplify the construction of the carts to reduce manufacturing costs and to improve the overall system value.
Accordingly, engineering challenges remain in the design of push-back cart storage systems.
It is therefore an object of the invention to provide an improved push-back cart storage system. Other and further objects and advantages will appear hereinafter.